When configuring GVRP, go to these sections
for information you are interested in:
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Introduction to GVRP
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GVRP Configuration
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Displaying and Maintaining
GVRP
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GVRP Configuration Example
GARP VLAN registration protocol (GVRP) is
an implementation of generic attribute registration protocol (GARP). GARP
is introduced as follows.
The generic attribute registration protocol
(GARP), provides a mechanism that allows participants in a GARP application to
distribute, propagate, and register with other participants in a bridged LAN
the attributes specific to the GARP application, such as the VLAN or multicast
attribute.
GARP itself does not exist on a device as
an entity. GARP-compliant application entities are called GARP applications.
One example is GVRP. When a GARP application entity is present on a port on
your device, this port is regarded a GARP application entity.
I. GARP messages and timers
1)
GARP messages
GARP members communicate with each other through
the messages exchanged between them. The messages performing important
functions for GARP fall into three types: Join, Leave and LeaveAll.
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When a GARP entity wants its attribute
information to be registered on other devices, it sends Join messages to these
devices. A GARP entity also sends Join messages when it receives Join messages
from other entities or it wants some of its statically configured attributes to
be registered on other GARP entities.
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When a GARP entity wants some of its attributes
to be deregistered on other devices, it sends Leave messages to these devices. A
GARP entity also sends Leave messages when it receives Leave messages from
other entities for deregistering some attributes or it has some attributes
statically deregistered.
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Once a GARP entity is launched, the LeaveAll
timer is triggered at the same time. The GARP entity sends out LeaveAll messages
after the timer times out. LeaveAll messages deregister all the attributes, through
which the attribute information of the entity can be registered again on the
other GARP entities.
Leave messages, LeaveAll messages, together
with Join messages ensure attribute information can be deregistered and re-registered.
Through message exchange, all the attribute
information to be registered can be propagated to all the GARP-enabled switches
in the same LAN.
2)
GARP timers
Timers determine the intervals of sending different
types of GARP messages. GARP defines four timers to control the period of
sending GARP messages.
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Hold: When a GARP entity receives a piece of
registration information, it does not send out a Join message immediately.
Instead, to save the bandwidth resources, it starts the Hold timer and puts all
received registration information before the timer times out into one Join
message and sends out the message after the timer times out.
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Join: To make sure the devices can receive Join
messages, each Join message is sent twice. If the first Join message sent is
not responded for a specific period, a second one is sent. The period is
determined by this timer.
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Leave: When a GARP entity expects to deregister
a piece of attribute information, it sends out a Leave message. Any GARP entity
receiving this message starts its Leave timer, and deregisters the attribute
information if it does not receives a Join message again before the timer times
out.
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LeaveAll: Once a GARP entity starts up, it starts
the LeaveAll timer, and sends out a LeaveALL message after the timer times out,
so that other GARP entities can re-register all the attribute information on
this entity. After that, the entity restarts the LeaveAll timer to begin a new
cycle.
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The settings of GARP timers apply to all GARP
applications, such as GVRP, on a LAN.
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Unlike other three timers, which are set on a
port basis, the LeaveAll timer is set in system view and takes effect globally.
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A GARP application entity may send LeaveAll
messages at the interval set by its LeaveAll timer or the LeaveAll timer on
another device on the network, whichever is smaller. This is because each time
a device on the network receives a LeaveAll message it resets its LeaveAll
timer.
II. Operating mechanism of GARP
Through the mechanism of GARP, the
configuration information on a GARP member will be propagated within the whole
LAN. A GARP member can be a terminal workstation or a bridge; it instructs
other GARP members to register/deregister its attribute information by
declaration/recant, and register/deregister other GARP member's attribute
information according to other member's declaration/recant. When a port
receives an attribute declaration, the port will register this attribute. When
a port receives an attribute recant, the port will deregister this attribute.
The protocol packets of GARP entities use
specific multicast MAC addresses as their destination MAC addresses. When
receiving these packets, the switch distinguishes them by their destination MAC
addresses and delivers them to different GARP application (for example, GVRP)
for further processing.
III. GARP message format
The GARP packets are in the following
format:
Figure 1-1 Format of GARP packets
The following table describes the fields of
a GARP packet.
Table 1-1 Description of GARP packet
fields
|
Field
|
Description
|
Value
|
|
Protocol ID
|
Protocol ID
|
1
|
|
Message
|
Each message consists of two parts:
Attribute Type and Attribute List.
|
—
|
|
Attribute Type
|
Defined by the specific GARP application
|
The attribute type of GVRP is 0x01.
|
|
Attribute List
|
It contains multiple attributes.
|
—
|
|
Attribute
|
Each general attribute consists of three
parts: Attribute Length, Attribute Event, and Attribute Value.
Each LeaveAll attribute consists of two
parts: Attribute Length and LeaveAll Event.
|
—
|
|
Attribute Length
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The length of the attribute
|
2 to 255 (in bytes)
|
|
Attribute Event
|
The event described by the attribute
|
0: LeaveAll Event
1: JoinEmpty
2: JoinIn
3: LeaveEmpty
4: LeaveIn
5: Empty
|
|
Attribute Value
|
The value of the attribute
|
For GVRP packets, the value of this field
is the VLAN ID; however, for LeaveAll messages, this field is invalid.
|
|
End Mark
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End mark of an GARP PDU
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The value of this field is fixed to 0x00.
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As an implementation
of GARP, GARP VLAN registration protocol (GVRP) maintains dynamic VLAN
registration information and propagates the information to the other switches through
GARP.
With GVRP enabled on a device, the VLAN
registration information received by the device from other devices is used to
dynamically update the local VLAN registration information, including the
information about the VLAN members, the ports through which the VLAN members
can be reached, and so on. The device also propagates the local VLAN
registration information to other devices so that all the devices in the same
LAN can have the same VLAN information. VLAN registration information
propagated by GVRP includes static VLAN registration information, which is manually
configured locally on each device, and dynamic VLAN registration information,
which is received from other devices.
GVRP has the following three port
registration modes: Normal, Fixed, and Forbidden, as described in the following.
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Normal. A port in this mode can dynamically
register/deregister VLANs and propagate dynamic/static VLAN information.
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Fixed. A port in this mode cannot
register/deregister VLANs dynamically. It only propagates static VLAN
information. Besides, the port permits only static VLANs, that is, it
propagates only static VLAN information to the other GARP members.
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Forbidden. A port in this mode cannot
register/deregister VLANs dynamically. It permits only the default VLAN
(namely, VLAN 1), that is, the port propagates only the information about VLAN
1 to the other GARP members.
GVRP is defined in IEEE 802.1Q standard.
Complete the following tasks to configure
GVRP:
I. Configuration Prerequisite
The port on which GVRP will be enabled must
be set to a trunk port.
II. Configuration procedure
Follow these steps to enable GVRP:
|
To do ...
|
Use the command ...
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Remarks
|
|
Enter system view
|
system-view
|
—
|
|
Enable GVRP globally
|
gvrp
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Required
By default, GVRP is disabled globally.
|
|
Enter Ethernet port view
|
interface interface-type interface-number
|
—
|
|
Enable GVRP on the port
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gvrp
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Required
By default, GVRP is disabled on the port.
|
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After you enable GVRP on a trunk port, you
cannot change the port to a different type.
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Use the port trunk permit all command to permit
the traffic of all dynamically registered VLANs to pass through a trunk port
with GVRP enabled.
Follow these steps to configure GVRP timers:
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To do ...
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Use the command ...
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Remarks
|
|
Enter system view
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system-view
|
—
|
|
Configure the LeaveAll timer
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garp timer leaveall timer-value
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Optional
By default, the LeaveAll timer is set to
1,000 centiseconds.
|
|
Enter Ethernet port view
|
interface interface-type interface-number
|
—
|
|
Configure the Hold, Join, and Leave
timers
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garp timer { hold | join | leave } timer-value
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Optional
By default, the Hold, Join, and Leave
timers are set to 10, 20, and 60 centiseconds respectively.
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Note that:
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The setting of each timer must be a multiple of
5 (in centiseconds).
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The timeout ranges of the timers vary depending
on the timeout values you set for other timers. If you want to set the timeout time
of a timer to a value out of the current range, you can set the timeout time of
the associated timer to another value to change the timeout range of this timer.
The following table describes the relations
between the timers:
Table 1-2 Relations between the timers
|
Timer
|
Lower threshold
|
Upper threshold
|
|
Hold
|
10 centiseconds
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This upper threshold is less than or
equal to one-half of the timeout time of the Join timer. You can change the
threshold by changing the timeout time of the Join timer.
|
|
Join
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This lower threshold is greater than or
equal to twice the timeout time of the Hold timer. You can change the
threshold by changing the timeout time of the Hold timer.
|
This upper threshold is less than
one-half of the timeout time of the Leave timer. You can change the threshold
by changing the timeout time of the Leave timer.
|
|
Leave
|
This lower threshold is greater than
twice the timeout time of the Join timer. You can change the threshold by
changing the timeout time of the Join timer.
|
This upper threshold is less than the timeout
time of the LeaveAll timer. You can change the threshold by changing the timeout
time of the LeaveAll timer.
|
|
LeaveAll
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This lower threshold is greater than the timeout
time of the Leave timer. You can change threshold by changing the timeout time
of the Leave timer.
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32,765 centiseconds
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The following are
recommended GVRP timer settings:
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GARP hold timer: 100 centiseconds (1 second)
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GARP Join timer: 600 centiseconds (6 seconds)
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GARP Leave timer: 3000 centiseconds (30 seconds)
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GARP LeaveAll timer: 120000 centiseconds (2
minutes)
Follow these steps to configure GVRP port
registration mode:
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To do ...
|
Use the command ...
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Remarks
|
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Enter system view
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system-view
|
—
|
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Enter Ethernet port view
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interface interface-type interface-number
|
—
|
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Configure GVRP port registration mode
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gvrp registration { fixed | forbidden | normal }
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Optional
By default, GVRP port registration mode
is normal.
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1.3 Displaying and Maintaining GVRP
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To do …
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Use the command …
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Remarks
|
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Display GARP statistics
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display garp
statistics [ interface interface-list ]
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Available in any view
|
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Display the settings of the GARP timers
|
display garp
timer [ interface interface-list ]
|
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Display GVRP statistics
|
display gvrp statistics [ interface interface-list ]
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Display the global GVRP status
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display gvrp status
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Clear GARP statistics
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reset garp statistics [ interface interface-list ]
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I. Network requirements
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Enable GVRP on all the switches in the network
so that the VLAN configurations on Switch C and Switch E can be applied to all
switches in the network, thus implementing dynamic VLAN information
registration and refresh.
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By configuring the GVRP registration modes of specific
Ethernet ports, you can enable the corresponding VLANs in the switched network
to communicate with each other.
II. Network diagram
Figure
1-2 Network diagram for GVRP configuration
III. Configuration procedure
1)
Configure Switch A
# Enable GVRP globally.
<SwitchA> system-view
[SwitchA] gvrp
# Configure GigabitEthernet1/0/1 to be a
trunk port and to permit the packets of all the VLANs.
[SwitchA] interface GigabitEthernet 1/0/1
[SwitchA-GigabitEthernet1/0/1] port link-type
trunk
[SwitchA-GigabitEthernet1/0/1] port trunk
permit vlan all
# Enable GVRP on GigabitEthernet1/0/1.
[SwitchA-GigabitEthernet1/0/1] gvrp
[SwitchA-GigabitEthernet1/0/1] quit
# Configure GigabitEthernet1/0/2 to be a
trunk port and to permit the packets of all the VLANs.
[SwitchA] interface GigabitEthernet 1/0/2
[SwitchA-GigabitEthernet1/0/2] port link-type
trunk
[SwitchA-GigabitEthernet1/0/2] port trunk
permit vlan all
# Enable GVRP on GigabitEthernet1/0/2.
[SwitchA-GigabitEthernet1/0/2] gvrp
[SwitchA-GigabitEthernet1/0/2] quit
# Configure GigabitEthernet1/0/3 to be a
trunk port and to permit the packets of all the VLANs.
[SwitchA] interface GigabitEthernet 1/0/3
[SwitchA-GigabitEthernet1/0/3] port link-type
trunk
[SwitchA-GigabitEthernet1/0/3] port trunk
permit vlan all
# Enable GVRP on GigabitEthernet1/0/3.
[SwitchA-GigabitEthernet1/0/3] gvrp
[SwitchA-GigabitEthernet1/0/3] quit
2)
Configure Switch B
# The configuration procedure of Switch B
is similar to that of Switch A and is thus omitted.
3)
Configure Switch C
# Enable GVRP on Switch C, which is similar
to that of Switch A and is thus omitted.
# Create VLAN 5.
[SwitchC] vlan 5
[SwitchC-vlan5] quit
4)
Configure Switch D
# Enable GVRP on Switch D, which is similar
to that of Switch A and is thus omitted.
# Create VLAN 8.
[SwitchD] vlan 8
[SwitchD-vlan8] quit
5)
Configure Switch E
# Enable GVRP on Switch E, which is similar
to that of Switch A and is thus omitted.
# Create VLAN 5 and VLAN 7.
[SwitchE] vlan 5
[SwitchE-vlan5] quit
[SwitchE] vlan 7
[SwitchE-vlan7] quit
6)
Display the VLAN information dynamically registered
on Switch A, Switch B, and Switch E.
# Display the VLAN information dynamically
registered on Switch A.
[SwitchA] display vlan dynamic
Total 3 dynamic VLAN exist(s).
The following dynamic VLANs exist:
5, 7, 8,
# Display the VLAN information dynamically
registered on Switch B.
[SwitchB] display vlan dynamic
Total 3 dynamic VLAN exist(s).
The following dynamic VLANs exist:
5, 7, 8,
# Display the VLAN information dynamically
registered on Switch E.
[SwitchE] display vlan dynamic
Total 1 dynamic VLAN exist(s).
The following dynamic VLANs exist:
8
7)
Configure GigabitEthernet1/0/1 on Switch E to operate
in fixed GVRP registration mode and display the VLAN information dynamically
registered on Switch A, Switch B, and Switch E.
# Configure GigabitEthernet1/0/1 on Switch
E to operate in fixed GVRP registration mode.
[SwitchE] interface GigabitEthernet 1/0/1
[SwitchE-GigabitEthernet1/0/1] gvrp registration
fixed
# Display the VLAN information dynamically
registered on Switch A.
[SwitchA] display vlan dynamic
Total 3 dynamic VLAN exist(s).
The following dynamic VLANs exist:
5, 7, 8,
# Display the VLAN information dynamically
registered on Switch B.
[SwitchB] display vlan dynamic
Total 3 dynamic VLAN exist(s).
The following dynamic VLANs exist:
5, 7, 8,
# Display the VLAN information dynamically
registered on Switch E.
[SwitchE-GigabitEthernet1/0/1]
display vlan dynamic
No dynamic vlans exist!
8)
Configure GigabitEthernet1/0/1 on Switch E to operate
in forbidden GVRP registration mode and display the VLAN registration
information dynamically registered on Switch A, Switch B, and Switch E.
# Configure GigabitEthernet1/0/1 on Switch
E to operate in forbidden GVRP registration mode.
[SwitchE-GigabitEthernet1/0/1] gvrp registration
forbidden
# Display the VLAN information dynamically
registered on Switch A.
[SwitchA] display vlan dynamic
Total 2 dynamic VLAN exist(s).
The following dynamic VLANs exist:
5, 8,
# Display the VLAN information dynamically
registered on Switch B.
[SwitchB] display vlan dynamic
Total 2 dynamic VLAN exist(s).
The following dynamic VLANs exist:
5, 8,
# Display the VLAN information dynamically
registered on Switch E.
[SwitchE] display vlan dynamic
No dynamic vlans exist!
